In a detailed statement provided to police, he said that when he was a teenager in the late 1960s he overheard a conversation between two men about the disposal of a girl's body near Granton, on the outskirts of Hobart.

He believes one of the men was convicted killer Geoffrey Charles Hunt.

Despite having the statement since at least January this year, police only spoke to the second man allegedly involved in the conversation after the ABC broke the story two weeks ago.

Police say they are reviewing the new information

Deputy Commissioner Scott Tilyard said "the latest piece of information has been investigated by police".

"A man was spoken to in relation to the information, however associated investigations did not reveal a specific line of inquiry. The information remains under review at this time," Mr Tilyard said.

"The enquiry remains open and police are still seeking information from the public regarding the disappearance of Lucille.

"Police remain in contact with the Butterworth family and this will continue."

But the family is not happy. It says members of the 2011 review of the case, praised by coroner Simon Cooper for their investigation, should have been tasked to investigate this lead and to vet any other tips that come in.

"How many other leads have not been pursued and followed through with?" Mr Butterworth said.

Mrs McDiarmid agreed, adding the entire community should be concerned.

"How many other cases out there are unsolved, which we know there are numerous well-known cases unsolved, has the same thing happened?" she said.

Police Commissioner Darren Hine formally apologised to the family in 2016 for what the coronial inquest found was "the myriad of deficiencies associated with the investigation in the past".

The family said the police handling of the case over the past year showed nothing had changed.